Vitamin D Retrospective Study and Role With Disease

The heightened prevalence of obesity in aging especially in postmenopausal women suggests that interventions to raise Vitamin D levels might be preventive of these diseases. Investigators have completed studies of the effects of weight loss and exercise interventions in approximately 400 older women and men over the last 15 years, many of whom are obese. Investigators have data on glucose tolerance, blood pressure and bone density in these studies and stored plasma in which investigators can analyze Vitamin D levels. Vitamin D may be an important risk factor for these metabolic diseases and the availability of these samples for Vitamin D analysis will allow investigators to perform a cross-sectional study to address relationships of Vitamin D levels to glucose intolerance and diabetes, hypertension/blood pressure status, bone mineral density, the degree of obesity, and physical activity status measured as maximal aerobic capacity and accelerometry in these older men and women.

The results of this study have the potential to impact clinical practice in the prevention and treatment of diabetes, hypertension, and osteopenia/osteoporosis. This would circumvent the current dilemma for prevention of these chronic diseases through treatment of obesity, as these data would provide immediate prospects for changing the recommended doses of Vitamin D beneficial for reducing risk for these diseases.

The purpose of this study is to 1) determine the prevalence of Vitamin D deficiency in obese, older men and postmenopausal women and 2) the association of Vitamin D levels to glucose tolerance, blood pressure, bone mineral density, and hyperlipidemia, as well as association with Vitamin D receptor gene polymorphisms affecting metabolic responses to Vitamin D.